Electric burglar-alarm.



No. 683,657. Patented Oct. I, I90I.

A. J. NUREEN.

ELECTRIC BURGLAR ALARM.

. (Appumm mi. 9, 1901.)

UNITED STATES PATENT OFFICE.

ALFRED JOIIAN NOREEN, OF CHICAGO, ILLINOIS.

ELECTRIC BU RGLAR-ALARM.

SPECIFICATION forming part of Letters Patent No. 683,657, dated October 1, 1901.

Application filed March 9 1901.

To all whom it may concern:

Be it known that I, ALFRED JOHAN No- REEN, a citizen of the United States of America, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Electric Burglar- Alarms, of which the following is a specification.

My invention relates to electric burglaralarms; and the main object of my invention is to provide an electric burglar-alarm suitable for use under rugs and carpets.

To this end I arrange a base-mat with a number of conductor-plates thereon connected with one pole of a battery and a number of contact-springs arranged above said plates normally out of contact with the plates and connected with the other pole of the battery, said battery being suitably connected with an alarm.

The further objects of the particular parts shown will be understood from the following description with reference to the accompanying drawings, in which- Figure 1 is a top plan of a rug and alarm constructed according to my invention, the rugbeing partly broken away. Fig. 2 is a side elevation of same, and Fig. 3 is a vertical section on the line :c of Fig. 1.

In the device shown the base-mat 1 has the metallic plates 2 xedly secured upon same. The plates are curved upwardly and inwardly at 3 and 4 to engage the spiral springs 5. The plates are insulated from the springs at the points of engagement by a layer of asbestos or other suitable insulating material. The plates are connected by the conductor-wire 7 with the bell 8 and with one pole of the battery 9. The springs 5 are connected by the wire 10 with the other pole of the battery 9. The wires 7 and 10 are each broken, with the two parts connected by the buttons 11 and 12, respectively. The central part 13 of each s'piral spring is normally raised from its respective plate 2, so as to be normally free from Contact with the plate except at the insulated ends 3 and 4. The springs and plates are covered with the mat or carpet 14, so that same are excluded from view. The bell and battery are located at any convenient place,

Serial No. 50,513. (No model.)

with the conductor-wires hidden under the fioor or carpet or in the walls in any desired manner. The buttons 11 and l2 are conveniently located, so that the connection with the alarm and battery may be broken when desired at either button by an operator linderstanding the devices. The wires 7 and 10 are suitably insulated from the mats.

rlhe operation of the device is as follows: WVhen the wires are connected, as shown, any pressure upon the mat 14, as by a person stepping upon same, will cause the central parts of the springs at 13, which are thereby depressed, to make contact with their respective plates 2, and thus complete the circuit between the alarm 8 and battery 9, causing the former to be sounded. The contact members, consisting of the plates and springs, are preferably located so near together that it would be impossible for a person to step upon the mat without sounding the alarm. When it is desired to set the device with the alarm out of circuit, the operator will discon# nect onev of the wires 7 or 10 at one of. the buttons 11 and 12.

It will be understood that the details of construction of the device shown may be altered in numerous ways without departing from the spirit of my invention. I therefore do not confine myself to such details.

What I claim as my invention, and desire to secure by Letters Patent, is-

Aburglar-alarm comprising abasemat, the conductor-plates iixedly secured thereto and having their ends rolled over as shown, the spiral springs engaged by and insulated from said ends, and having their central portions normally raised from said plates, an electric battery, a llexible coveringmat over said plates being connected with one pole of the battery,and said springs being connected with the other pole of the battery, and an alarm in circuit with said plates, springs, and battery, all l ALFRED JOHAN NOREEN.

Witnesses:

GUs'rAF A. NOREEN, MARIA NOREEN. 

